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Original Article


Cross-reactivity and Tolerability of Ertapenem in Patients With IgE-Mediated Hypersensitivity to β-Lactams


Buonomo A*, Pascolini L*, Rizzi A, Aruanno A, Pecora V, Ricci AG, Mezzacappa S, Di Rienzo A, Centrone M, Nucera E, Schiavino D

Department of Allergy, Università Cattolica del Sacro Cuore, Rome, Italy
*These authors contributed equally to the manuscript

J Investig Allergol Clin Immunol 2016; Vol. 26(2): 100-105
doi: 10.18176/jiaci.0019



Background and Objective: Administration of carbapenems to β-lactam-allergic patients has always been considered potentially harmful because of a 47.4% rate of cross-reactivity to imipenem reported in a single study. Nevertheless, recent studies have shown that the rate of cross-reactivity of imipenem and meropenem with penicillins is lower than 1%. The aim of this study was to evaluate the possibility of using ertapenem in patients with an established IgE-mediated β-lactam allergy.

Patients and Methods: We studied all participants who came to our allergy unit and had a clinical history of immediate hypersensitivity reactions to β-lactams. The inclusion criteria were a positive skin test result to at least 1 β-lactam molecule and/or positive specific IgE (when available). All participants underwent immediate-type skin tests with several β-lactam molecules including ertapenem. Challenges with intravenous ertapenem were performed on 2 different days in patients with negative skin test results.

Results: We examined 49 patients with a clinical history of immediate reactions to β-lactams. All the patients had positive skin tests and/or positive specific IgE to at least 1 β-lactam reagent and negative carbapenem skin tests. Thirty-six patients agreed to undergo the challenges and 35 tolerated the full dose of ertapenem.

Conclusions: The practice of avoiding carbapenems in patients with β-lactam allergy should be abandoned considering the very low rate of cross-reactivity. β-Lactam-allergic patients who need ertapenem therapy should undergo skin tests and, if negative, a graded challenge to assess tolerability.

Key words: β-lactams. IgE-mediated hypersensitivity. Ertapenem. Cross-reactivity.